Disc brake with noise arrester

ABSTRACT

A disc brake including a noise arrester means that dampens vibrations between the brake pad backing plate and the caliper assembly. The noise arrester comprises a spring metal clip that engages the end of the backing plate and exerts a spring force on an abutment tab protruding from the backside of the brake pad backing plate.

tates Flaherty et a1.

atet

[54] DISC BRAKE WITH NOISE ARRESTER [72] inventors: Bernard M. Flaherty,Birmingham; Lewis L. Knight, Allen Park, both of Mich.

[73] Assignee: Ford Motor Company, Dearbom, Mich.

[22] Filed: Mar. 18, 1970 [21] Appl. No.: 20,692

[52] US. Cl ..188/73.5

[51] Int. Cl ..F16cl 65/00 [58] Field ofSearch... ......l88/73.5, 73.6,205 A [56] References Cited UNITED STATES PATENTS Miles s 188/736 Feb.l, 1972 l/1970 Hahm ..l88/73.5 4/1970 Anders ..l88/73.5

Primary ExaminerGeorge E. A. Halvosa Att0mey]ohn R. Faulkner and RogerE. Erickson [5 7] ABSTRACT A disc brake including a noise arrester meansthat dampens vibrations between the brake pad backing plate and thecaliper assembly. The noise arrester comprises a spring metal clip thatengages the end of the backing plate and exerts a spring force on anabutment tab protruding from the backside of the brake pad backingplate.

7 Claims, 4 Drawing Figures DISC BRAKE WITH NOISE ARRESTER BACKGROUND OFTHE INVENTION Automotive vehicles equipped with disc brakes may undercertain conditions experience brake squeal during light brakeapplications. Such a squeal is generally caused by highfrequencyvibrations of the metal backing plate of the brake pad against thecaliper assembly.

One attempted solution to this problem has been to cover the backside ofthe backing plate with a thin layer of an asbestos or similar insulatingmaterial. This method is not completely satisfactory as it is notpossible to effectively insulate the high force transmission areas ofthe backing plate.

This invention provides a disc brake construction including a noisearrester which dampens vibrations between the pad backing plate and thecaliper assembly so as to reduce causes of brake squeal. It alsoprovides a noise arrester not subject to wear as would be an asbestosinsulating layer. Furthermore, this invention provides a noise arresterfor a disc brake which can be installed either in initial production oras a service item and which is economical to manufacture and reliable inoperatron.

SUMMARY OF THE INVENTION A disc brake constructed in accordance withthis invention includes a caliper member, a pad assembly including ametal backing plate, one or more abutment tabs protruding from thebackside of the backing plate engageable with the caliper assembly.Secured to the backside of the backing plate is a noise arrester cliphaving a shimlike portion engageable with an abutment tab and a springportion engageable with an end of the backing plate. The spring portionurges an edge of the shimlike portion into engagement with the abutmenttab. The shimlike portion may be bonded to the backing plate.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of abrake pad assembly showing the metal backing plate and the noisearrester clip attached thereto.

FIG. 2 is a cross section taken through line 2-2 of FIG. 1.

FIG. 3 is a bottom view with portions removed of a disk brake caliperassembly embodying the invention.

FIG. 4 is a side view ofa portion of the caliper member 14 in thedirection of arrow 4 in FIG. 3. Clip 24 is shown displaced 90 from itsposition in FIG. 3 to unobstructedly show slot 32.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A disc brakefloating-type caliper assembly, shown in FIG. 3, includes an anchorplate 12, a caliper member 14 slidably connected to the anchor plate, aninner brakeshoe or pad assembly l6 and an outer brakeshoe or padassembly 18. The anchor plate includes a housing which slidably receivesan actuating piston (not shown). The piston upon actuation urges theinner pad assembly 16 toward the outer pad assembly 18 so that the brakerotor (not shown) attached to a vehicle wheel is engaged and vehiclebraking is effected. The caliper member 14, being slidably mountedrelative to the anchor plate 12, together with the pad assembliesprovide a balanced clamping of the brake rotor. A pair of pins 22 andclips 24 secure the outer brake pad assembly 18 to the outer portion ofthe caliper member 14.

The outer brake pad assembly 18 comprises a friction pad 26 bonded to ametal backing plate 28. A pair of abutment tabs 30 protrude obliquelyfrom the backside of the backing plate and extend into a pair ofcorresponding axially disposed slots 32 formed in the caliper member.These tabs function as reaction abutments to transfer tangential forcesfrom the brake rotor through the shoe assembly to the caliper member.Abutment tabs such as these have been found to be a source ofhigh-frequency squeal vibrations upon light brake application. It hasbeen further found that these vibrations map be dampened to the extentthat they no longer produce an audible squeal by the use of a noisearrester such as shown in detail in FIGS. 1 and 2 of the drawing, andinstalled in the caliper assembly as shown in the FIGS. 3 and 4 of thedrawings.

The noise arrester clip 34 has a generally flat shimlike portion 36 witha section removed to provide an opening 38 which receives the abutmenttab 30 of the brake pad backing plate. A loop-spring portion 40 of thenoise arrester clip engages a V-groove 42 formed in the end of thebacking plate and resiliently urges an edge 44 of the opening intoengagement with the underside of the abutment tab 30. A pair of locatingtabs 46 position the noise arrester clip relative to the backing plate.To function properly and effectively, the noise arrester clip mustengage the underside of the tab 30 along edge 44 and the backing plate28 along its flat back. In many applications, it has been found that theclip is more effective in preventing audible vibrations if the shimlikeportion 36 that engages the backside of the backing plate is bonded tothe backing plate by a suitable adhesive. A thermoset bonding materialhaving elastometric characteristics sufficient to accommodatedeformations of the backing plate and the abutment tab, but yet not sopliable that the noise arrester clip shifts so far that its significantdampening characteristics are lost, has been found to be satisfactory.In the preferred embodiment, the angle of the abutment tab 30 relativeto the remainder of the backing plate backside where it is engaged bythe edge 44 is at approximately 35 to It has been found that springsteel shim stock of approximately about 0.0I0-inch thickness issatisfactory to fabricate the noise arrester clip.

OPERATION This invention has been widely tested and used and is found toeffectively reduce causes of audible vibrations or squeal during vehiclebraking.

As indicated previously, the noise arrester clip must engage theunderside of tab 30 along edge 44 and the backing plate 28 along itsflat back. It is believed that the shimlike portion 36 of clip 34functions as a dampener of the scissors-type vibrational movementsbetween tab 30 and the remainder of backing plate 28, thereby affectingvibrations within the brake assembly.

The foregoing presents a preferred embodiment of the invention.Modifications and alterations will occur to those skilled in the artwhich are included within the scope of the following claims:

I claim:

1. A brake including:

a brake pad assembly associated with a caliper assembly and having abacking plate and a friction pad secured to one side of said backingplate,

said backing plate having at least one abutment tab protruding acutelyfrom its other side;

a noise arrestor having a shimlike portion interposing said other sideof the backing plate and said caliper assembly, said shimlike portionhaving a plane parallel to said other side of the backing plate;

an opening formed in the shimlike portion through which said abutmentmeans protrudes, said opening including an edge engageable with anabutment tab along its line of intersection with the plane of said otherside of the backing plate; and

spring means engageable with said backing plate to urge said edge intoengagement with said abutment tab.

2. In a disc brake according to claim 1;

means to bond said shimlike portion of said noise arrester to saidbacking plate.

3. A brake including:

a brake pad assembly associated with a caliper assembly and having abacking plate and a friction pad secured to one side of said backingplate;

said backing plate having at least one abutment tab protruding acutelyfrom its other side;

a noise arrestor having a shimlike portion interposing said other sideof the backing plate and said caliper assembly, said shimlike portionhaving a plane parallel to said other side of the backing plate;

said shimlike portion including an edge engageable with an abutment tabalong its line of intersection with the plane of said other side of thebacking plate; and

spring means engageable with said backing plate to urge said edge intoengagement with said abutment tab.

4. In a disc brake according to claim 3;

means to bond said shimlike portion of said noise arrester to saidbacking plate.

5. In a disc brake having a caliper member, a brake pad assembly mountedon said caliper member including a backing plate and a friction padsecured to one side thereof;

a pair of abutment means protruding from the other side of said backingplate and being engageable with said caliper member to prevent movementof said brake pad assembly relative to caliper member in predetermineddirections;

a pair of noise arresters each having a shimlike portion interposingsaid other side of the backing plate and said caliper assembly, saidshimlike portions having a plane parallel to said other side of thebacking plate;

an opening formed in each said shimlike portion receiving one of saidabutment means, said opening including an edge engageable with anabutment tab along the line of intersection with the plane of said otherside of the backing plate; and

spring means engageable with said backing plate to urge said edge ofeach said opening into engagement with each of said abutment means.

6. In a disc brake according to claim 5;

means to bond each said shimlike portion of said noise arresters to saidbacking plate.

7. In a disc brake according to claim 6;

each of said abutment means comprising a tab forming an angle of lessthan with the backing plate,

said tabs sloping in generally opposite directions; and

the ends of said tabs being engageable with said caliper member.

1. A brake including: a brake pad assembly associated with a caliperassembly and having a backing plate and a friction pad secured to oneside of said backing plate, said backing plate having at least oneabutment tab protruding acutely from its other side; a noise arrestorhaving a shimlike portion interposing said other side of the backingplate and said caliper assembly, said shimlike portion having a planeparallel to said other side of the backing plate; an opening formed inthe shimlike portion through which said abutment means protrudes, saidopening including an edge engageable with an abutment tab along its lineof intersection with the plane of said other side of the backing plate;and spring means engageable with said backing plate to urge said edgeinto engagement with said abutment tab.
 2. In a disc Brake according toclaim 1; means to bond said shimlike portion of said noise arrester tosaid backing plate.
 3. A brake including: a brake pad assemblyassociated with a caliper assembly and having a backing plate and afriction pad secured to one side of said backing plate; said backingplate having at least one abutment tab protruding acutely from its otherside; a noise arrestor having a shimlike portion interposing said otherside of the backing plate and said caliper assembly, said shimlikeportion having a plane parallel to said other side of the backing plate;said shimlike portion including an edge engageable with an abutment tabalong its line of intersection with the plane of said other side of thebacking plate; and spring means engageable with said backing plate tourge said edge into engagement with said abutment tab.
 4. In a discbrake according to claim 3; means to bond said shimlike portion of saidnoise arrester to said backing plate.
 5. In a disc brake having acaliper member, a brake pad assembly mounted on said caliper memberincluding a backing plate and a friction pad secured to one sidethereof; a pair of abutment means protruding from the other side of saidbacking plate and being engageable with said caliper member to preventmovement of said brake pad assembly relative to caliper member inpredetermined directions; a pair of noise arresters each having ashimlike portion interposing said other side of the backing plate andsaid caliper assembly, said shimlike portions having a plane parallel tosaid other side of the backing plate; an opening formed in each saidshimlike portion receiving one of said abutment means, said openingincluding an edge engageable with an abutment tab along the line ofintersection with the plane of said other side of the backing plate; andspring means engageable with said backing plate to urge said edge ofeach said opening into engagement with each of said abutment means. 6.In a disc brake according to claim 5; means to bond each said shimlikeportion of said noise arresters to said backing plate.
 7. In a discbrake according to claim 6; each of said abutment means comprising a tabforming an angle of less than 90* with the backing plate, said tabssloping in generally opposite directions; and the ends of said tabsbeing engageable with said caliper member.